The present invention relates to hybrid construction equipment.
Recently, following an increase in construction operations in city areas, various arts of improving operation environments such as exhaust gas and noise of construction equipment are proposed. For example, Japanese Patent Application Laid-open No. 2000-226183 discloses an art regarding a hybrid type of working vehicle.
Specifically, as shown in FIG. 7, electric power generated by a generator 52 driven with an engine 51 as a power source is charged to a battery 54 via a battery charger 53, and an electric motor 56 is driven via an inverter 55 by charged electric power to drive a hydraulic pump 57 for driving an working machine. Further, a hydraulic pump 59 driven by the engine 51 via a clutch 58 is included. By switching a working machine driving mode, drive of the hydraulic pumps 57 and 59 is switched to xe2x80x9cbattery drivexe2x80x9d, xe2x80x9cengine drivexe2x80x9d, and xe2x80x9cengine drive and assist drive by batteryxe2x80x9d to realize noise reduction according to an operation content and an operation site.
Further, in order to perform operations in city areas, construction equipment needs to have a compact outside shape, and therefore each device mounted thereon is required to be compact. As a large-capacity battery for hybrid construction equipment conventionally requiring a large volume, a battery excellent in input-output characteristics (for example, a lithium ion cell, a nickel-hydrogen fuel cell and the like) is considered to be adopted. Since this kind of battery is susceptible to temperature, the temperature control for the battery is very tight in order to exhibit the performance, and a battery controller attached to the battery controls charge and discharge of electricity by always monitoring voltage, electric current, temperature and the like of the battery.
However, in the conventional hybrid construction equipment, a battery is installed near heating units such as an engine, a hydraulic apparatus and the like, and no consideration is given to installation method and installation place for performing temperature control of the battery, whereby there arises the disadvantage that it does not have the constitution in which the performance of the battery is sufficiently exhibited.
The present invention is made in view of the above-described disadvantage, and its object is to provide hybrid construction equipment capable of sufficiently exhibiting performance of a battery by carrying out strategic arrangement of apparatuses and temperature control of the battery.
In order to attain the above-described object, hybrid construction equipment according to the present invention includes, on an upper revolving superstructure rotatably placed on a lower traveling unit, an engine, a generator driven by the engine, a battery charged with generated electric power by the generator, an electric motor driven by electric power of the battery, an inverter for controlling drive of the electric motor, and a driver""s cab, and the battery is placed to be isolated from the engine and the generator.
According to the above constitution, the battery is placed to be isolated from the heating units such as the engine and the like, and therefore the battery hardly has high temperature. Consequently, reduction in performance and life of the battery caused by the high temperature of the battery can be prevented, and the performance of the battery can be sufficiently exhibited.
Further, in the hybrid construction equipment, the battery is placed inside an upper revolving superstructure frame under the driver""s cab. Furthermore, in the hybrid construction equipment, the engine, the generator and a fuel tank are placed in a machine room at a rear part of the upper revolving superstructure, and a working fluid tank and an operation valve for operating a hydraulic pump driven by the engine are placed at a right side of a front part of the upper revolving superstructure.
According to the above constitution, the battery is placed in the frame of the upper revolving superstructure under the driver""s cab, which is the place without the heating units around it, and therefore the battery hardly has high temperature, thus making it possible to sufficiently exhibit the performance of the battery. Further, since the fuel tank is placed near the engine and the working fluid tank is placed near the operation valve, the fuel pipe line and the drain pipe line can be shortened, thus making it possible to facilitate the assembly and reduce the system in size.
Furthermore, in the hybrid construction equipment, a battery housing chamber, which includes a cooling air inlet port communicating with the driver""s cab and a cooling air outlet port, is provided inside an upper revolving superstructure frame under the driver""s cab, and the battery is housed in the battery housing chamber.
According to the above constitution, the battery housing chamber is provided inside the upper revolving superstructure frame under the driver""s cab, which is the place isolated from the heating units such as the engine and the like, and this battery housing chamber further includes the cooling air inlet port communicating with the driver""s cab and the cooling air outlet port. Consequently, it is made possible to introduce cooling air and control the temperature of the battery at suitable temperature, and thus the performance of the battery can be exhibited more sufficiently.
Further, in the hybrid construction equipment, the inverter is housed in any one of xe2x80x9can air intake chamber communicating with a radiatorxe2x80x9d, xe2x80x9can inverter housing chamber provided at a rear part of the driver""s cabxe2x80x9d, and xe2x80x9ca battery housing chamberxe2x80x9d.
According to the above constitution, the inverter susceptible to high temperature as the battery is housed in the air intake chamber, the inverter housing chamber, or the battery housing chamber, which is isolated from the heating units such as the engine and the like, and therefore the inverter hardly has high temperature. Further, the inverter can be cooled by the engine cooling air, the driver""s cab cooling air, or the battery cooling air, thus making it possible to maintain the inverter at suitable temperature and sufficiently exhibit the performance of the inverter. Furthermore, since the battery and the inverter are placed around the driver""s cab, the wiring connecting each other is shortened and the assembly is facilitated.